The company reported a loss of $87.9 million, or 20 cents per Class C share, in the quarter ended Dec. 31, compared with a profit of $103.2 million, or 23 cents per share, a year earlier.

The reported quarter included a one-time charge of $39 million due to changes in the U.S. tax code.

The sportswear maker, that competes with Nike Inc and Adidas AG, said it would incur additional restructuring charges between $110 million and $130 million this year, related to closing of facilities and termination of leases.

Archives Under Armour

The US athletic footwear sector grew by 2 per cent last year, generating $19.6 billion in sales, according to The NPD Group. Unit sales grew by 2 per cent and average selling price remained flat, at $58.16.

​Britons are spending more and more money on activewear and many have seen their spend soaring in only the last year as running and gym workouts in particular have become more popular than ever before.